Optimizing type 1 diabetes after multiple daily injections and capillary blood monitoring: Pump or sensor first? A meta-analysis using pooled differences in outcome measures

Aims Most people living with type 1 diabetes self-manage using multiple daily injection (MDI) insulin regimens and self-monitoring of blood glucose (SMBG). Continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring (CGM) are adjuncts to education and support self-management optimization. The aim of this systematic review and meta-analysis was to assess which first-line technology is most effective. Methods Electronic databases (MEDLINE, EMBASE and WEB OF SCIENCE) were systematically searched from 1999 to September 2020. Randomized controlled trials comparing either CSII with MDI or CGM with SMBG in adults with type 1 diabetes were included. Data were extracted in duplicate by two reviewers, and were analysed to assess individual and overall treatment effect measures (PROSPERO registration: CRD42020149915). Results Glycated haemoglobin was significantly reduced for CGM when compared with SMBG [Cohen's d - 0.62 (95% CI -0.79 to -0.45)] and for CSII when compared with MDI [Cohen's d - 0.44 (95% CI -0.67 to -0.22)]. Rates of severe hypoglycaemia were significantly reduced with CGM compared with SMBG, but did not change for CSII when compared with MDI. Episodes of diabetic ketoacidosis were more likely to occur with CSII than MDI. Both CSII and CGM reduced glucose standard deviation, compared with MDI and SMBG respectively. Conclusions Both CGM and CSII remain impactful interventions compared with SMBG and MDI but in adults with type 1 diabetes and in the contexts in which they have been studied, CGM might have a greater positive impact on glycaemic variability and severe hypoglycaemia than CSII, when added to MDI and SMBG. A head-to-head study, including patient reported outcomes, is required to explore these findings further.

Automated summary

This systematic review and meta-analysis found that compared to MDI, CSII can significantly reduce glycated haemoglobin levels, and compared to SMBG, CGM can also significantly reduce glycated haemoglobin levels. CGM is more effective in reducing severe hypoglycemia compared to SMBG, while CSII does not show a significant change in severe hypoglycemia compared to MDI. Additionally, CSII is associated with a higher risk of diabetic ketoacidosis. Both CSII and CGM are effective interventions, but CGM may have a greater impact on reducing glycaemic variability and severe hypoglycaemia in adults with type 1 diabetes.